The present invention is directed to a method of bonding a plurality of electrical leads to a plurality of pads or electrical contacts aligned with a surface of an electrical component. And more particularly, the present method is directed to bonding a plurality of electrical leads of a TAB tape to a plurality of electrical contacts or pads on the surface of an integrated circuit die or chip without requiring bumps on the die, bumps on the leads, or transfer bumps.
It is conventional to bond tape automated bonding (TAB) tape having a plurality of electrical leads to integrated circuit dies by thermocompression bonding such as shown in U.S. Pat. No. 4,776,509 or laser bonding as shown in U.S. Pat. No. 4,845,335. However, such bonding generally requires the use of a bump on the electrical pads or contacts of the integrated circuit die and/or on the electrical TAB leads.
The present invention is directed to a method for providing contact bumps necessary to prevent contact beam leads or other substrate circuitry from touching the semiconductor silicon surface of a die. This simpler, easier, and more cost effective method of bonding eliminates the cost, possible wafer loss in processing, and the capital cost of an electroplating bumping line for plating bumps on wafers to be bonded. The present invention is particularly well suited for flip chip bonding.